Yarn



Patented Feb. 4, 1936 y UNITED STATES PATENT OFFICE YARN Leo Wallerstein, Rowland A. Gale, and Thomas G.

Hawley, In, New York, N. Y., assignors to Wallerstein Company Inc., a corporation of New York No Drawing. Application April 26, 1934,

I Serial No. 722,506

2 Claims. (Cl. 91-68) The present invention relates to the manufachas been impregnated with hygroscopic agents ture of silk fabrics, particularly from natural will always take up moisture from'the atmossilk in gum. Raw silk, as is ordinarily obtained phere and will always be moist and damp. from Japan to the United States is encased in its According to the present process, however, the

5 natural gum. It is desirable to keep this gum silk after having been made absorbent with upon the fibres throughout the textile forming treatment of the enzymatic composition remains operations, such as winding, doubling, twisting, dry and does not tend .to absorb moisture from knitting, and/or weaving, since the added body the air. In addition, the enzymatic treatment which this gives to the silk has been found parof the present invention actually increases the ticularly desirable in many operations. amount of moisture absorbent surface on the gum 10 This raw silk largely is received in this country coating, while according to the prior methods in skeins and these skeins are unwound and then employing hygroscopic agents and/or wettingsubjected to winding, doubling and twisting. out agents, the moisture absorbing surface is no This twisted yarn is then utilized for knitting greater than before.

16 purposes. In knitting it is desirable that a cer- In the preferred procedure, the natural silk in tain amount of moisture be applied to the threads yarn or skein form, is dipped into a bath of a so as to make them bend more readily and form temperature below 50 (1., said bath containing more satisfactory loops in the knitting operation. in solution and/or in suspension the proteolytic The natural silk on the gum is not particularly enzyme preparation with which may be prefer- 20 water-absorbent and it is particularly difiicult to ably combined the alkali metal salt or salts of 20 make it take up a. desirable amount of water by a high molecular weight fatty acid or fatty acids, the usual methods. or the alkali metal salt of high molecular weight,

To improve the moisture absorbing qualities of sulphuric or sulphonic acids of aliphatic, aromatic, the gum coating on the raw silk, it has been found and alicyclic compounds of high molecular desirable to impregnate the silk, preferably in weight; sulfonated oils; or other wetting-out 25 the form of its skeins, before winding, doubling, agents. Some raw oil is generally emulsified in and/or twisting by hygroscopic agents, such as the solution for lubricating purposes. glycerine and/or by the application of wetting Among the compounds which may be used are out agents, such as sulphonated oils. Both of sodium oleate, sodium palmitate, sodium stearate,

these methods, however, are in reality merely sodium hexadecyl sulphonate, neats-foot oil, 30

surface applications) .Turkey red oil,- raw vegetable oils, such as olein,

The quantity of these wetting-out agents or and so forth. hygroscopic agents which may be utilized is lim- The skein or yarn may be suspended in the ited since the gum will only take up relatively soaking bath for a sufiicient length of time to small quantities thereof, and moreover, these assure that the anzyme preparation and the 35 agents are not only expensive but from many other ingredients have thoroughly penetrated'the aspects may be undesirable to have present in gum in the silk, and at all times the temperature certain manufacturing operations. and pH should be so maintained that substan- It has now been found that the gum of the tially no degumming action results.

40 silk may be rendered highly absorbent, by treat- The soaking may be carried out from 30 min- 40 ment of such silk with certain types of enzymatic utes to 16 hours, and it preferably should not be preparations, particularly of a proteolytic nacarried out for longer than 24 hours. The skein ture. These proteolytic enzyme solutions or or yarn after being so impregnated with the enpreparations are preferably applied in the form zyme preparation is centrifuged so as to remove 45 of a bath to the silk skeins, with the addition of as much moisture as possible and then is thorwetting-out agents, such as sulphonated oils for oughly or partly dried before being subjected to proper enzyme distribution. These proteolytic further textile forming operations.

enzyme compositions appear to cause a. physical Various protease preparations may be used in change in the sericin or silk gum making it highcarrying out the process, such as protease prep- 1y porous so that it will absorb water in a manarations derived from micro-organisms which un- 50 ner similar to a sponge. The increase in abde'r suitable culture conditions develop proteolytic sorbent properties of the gum by reason of the enzymes, as for instance, preparations derived proteolytic treatment is much moresatisfactory from Aspergillus oryzw, from cultivation of bacthan when the hygroscopic agents or wetting-out teria, such as B. mesentericus, B. mycoides, or agents are employed. For example, silk which B. subtilis, or Mucor delemar, Amylomyces, 55

Rouxii, Penecillium, and so forth. Other suitable proteolytic enzymes may be used, such as papain, bromelin, malt enzymes, trypsin, or pepsin. Suitable mixtures of the above described enzymes may also be used.

As examples in carrying out the process, one may proceed as follows:

Example 1.-100 pounds oiraw silk are soaked from minutes to 1 hour in a bath or solution consisting oi .400 pounds of water in which have been dissolved pounds of the bacterial enzyme preparation, 1 pound of sodium sulflte for eiiecting a suitable pH, and 1 pound of sulionated oil, this latter material being used to effect a better penetration, or as it is technically called, a wetting-out of the fibre, though it will be understood that other penetrants can be used for eiifecting this wetting-out such as a small amount 01' soap.

It the soaking period is increased, the amount of enzyme may be decreased, as for example, with over-night soaking only half as much enzyme is required.

Other suitable pH regulators, for instance, sodium carbonate or bicarbonate, or a mixture thereof, may be used instead of the sodium sulflte referred to.

Emulsions of common soaking oils, such as neats i'oot oil, may also be used in conjunction with enzymes.

The temperature at which this process is carried out may be advantageously varied with the time consumed in the operation, the nature or origin of the silk, the nature 01' the particular enzyme employed, and the presence of other con stituents, such as pH regulators. However, we generally employ this process at room temperature, that is, from to F.

The silk is then removed from the enzyme bath and the adhering liquor is removed in any. suitable manner, as by centrifuging, and after the centriiugingstepthesilkflbresaredriedata low temperature by an air blast or any other suitable method.

Erample 2. pounds oi 13/15 Japan white silkinthegumaresoakedior30minutesat room temperature in 400 pounds of water solution containing 5 pounds of papain, 4 pounds oi sulionated oil, 0.05 pound of potassium cyanide, and 2 pounds of mono-sodium vphosphate. It is then centrifuged and air dried.

Example 3.--100 pounds of 13/15 Japan white silk in the gum are soaked for 30 minutes at room temperature in 400 pounds of water solution containing 5 pounds of pancreatin, 1 pound oi sodium sulfite, and suitable penetrants and oils. It is then centrifuged and air dried.

The present application is a continuation in part of application Serial No. 606,286, filed April 19, 1932, and is similar in subject matter to copending applications Serial Nos. 722,504, 722,505, 722,507 and 722,508, all filed April 26, 1934.

The present application is particularly directed to yarns for knitting, weaving and other textile processing, in which the natural silk in gum has been treated to give it enhanced moisture absorptiye properties.

What is claimed is:

1. A yarn composed of natural silk in gum and impregnated with'a proteolytic enzyme, said yarn having enhanced absorptive properties and the gum on said yam having substantially the original body-giving properties in respect to textile processing, said yarn being particularly adapted for knitting; weaving, and other textileoperations.

2. A process of enhancing yarns to adapt them for knitting, weaving, and other textile processing, which consists in impregnating natural silk in gum with a proteolytic enzyme and leaving the gum in substantially its original condition in respect to body-giving conditions after such impregnation and which comprises immersing the natural silk in gum in an aqueous bath containing the enzyme at about room temperature and at a temperature below 50 C. for between thirty minutes to twenty-four hours, then removing the enzyme-impregnated natural silk in gum and drying the same.

LEO WALLERSTEIN. ROWLAND A. GALE. THOMAS G. HAWLEY, Jr. 

